Unless otherwise indicated herein, the description provided in this section is not itself prior art to the claims and is not admitted to be prior art by inclusion in this section.
A typical radio access network (RAN) includes one or more base stations that radiate to define one or more wireless coverage areas, such as cells and cell sectors, in which user equipment devices (UEs) such as cell phones, tablet computers, tracking devices, embedded wireless modules, and other wirelessly equipped communication devices, can operate. Further, each base station of the RAN may then be coupled or communicatively linked with network infrastructure such as a switch or gateway that provides connectivity with one or more transport networks, such as the public switched telephone network (PSTN) and/or the Internet for instance.
With this arrangement, a UE within coverage of the RAN may thus engage in air interface communication with the base station and thereby communicate via the base station with various remote network entities or with other UEs served by the base station.
In general, a RAN may operate in accordance with a particular air interface protocol or radio access technology, with communications from a base station to UEs defining a downlink or forward link and communications from the UEs to the base station defining an uplink or reverse link. Examples of existing air interface protocols include, without limitation, Orthogonal Frequency Division Multiple Access (OFDMA) (e.g., Long Term Evolution (LTE) or Wireless Interoperability for Microwave Access (WiMAX)), Code Division Multiple Access (CDMA) (e.g., 1 xRTT and 1xEV-DO), Global System for Mobile Communication (GSM), WI-FI, and BLUETOOTH. Each protocol may define its own procedures for registration of UEs, initiation of communications, handoff between coverage areas, and functions related to air interface communication.
When a UE enters into coverage of a RAN, the UE may detect a reference signal and read system information broadcast from a base station and may then engage in a process to register itself to be served by the RAN. For instance, the UE may transmit an attach message on an uplink control channel to the base station, and the base station and/or supporting infrastructure may then responsively authenticate and authorize the UE for service and establish a record indicating where in the RAN the UE is operating and provide an attach accept message to the UE. Thereafter, the UE may then be served by the RAN in an idle mode or a connected/active mode. In the idle mode, the UE may monitor a downlink control channel to detect page messages and other information regarding incoming communications and may similarly transmit uplink control signaling to initiate communications or for other reasons. In the connected/active mode, the UE may have particular traffic channel resources assigned by the RAN, which the UE may use to engage in communication of bearer traffic and the like.
A communications system may accommodate multiple RANs, such as CDMA networks, LTE networks, and wireless Local Area Networks (wireless LANs), in a partially or fully integrated manner. Further, the communication system may provide for UE mobility among such RANs. This mobility may allow for transmission, reception, and continuous communication even when the UE moves from one RAN to another.